Low-tech hand washing can cut the rate of diarrheal infections in children living in developing countries, researchers have found.

Giving people soap and hand washing instructions reduced the incidence of diarrhea by more than 50 per cent among children in Pakistan, the team reported in Wednesday's global health-themed issue of The Journal of the American Medical Association.

Nearly two million children worldwide die from diarrheal disease each year, according to the World Health Organization.

Hand washing with soap physically removes pathogens

"We found that hand washing with soap markedly reduced diarrhea despite a highly contaminated environment, despite highly contaminated wash water and without any clean towels," Dr. Stephen Luby of the U.S. Centers for Disease Control told a news conference.

Many of the children who die are too young to wash their own hands. Luby's team tested whether teaching family members to keep their hands clean helped infants.

The study was conducted among 36 low-income settlements in Karachi, Pakistan, from April 2002 to April 2003.

Field workers visited at least weekly to tell 600 households about the importance of proper hand washing using slide shows, videos and pamphlets. A control group of 306 households received school supplies such as pencils and notebooks.

The researchers found children younger than 15 in the soap group had a 53 per cent lower incidence of diarrhea compared to those who didn't receive soap and education.

Infants in the soap homes had 39 per cent fewer days with diarrhea than those in the control neighbourhoods.

Half of the soap group used antibacterial soap, but it didn't make a difference. Luby expected it wouldn't since antibacterial soap doesn't kill the bacteria and virus that usually cause diarrhea.

The authors said the next step is to reduce the costs of the program so it can reach millions at risk worldwide.

Procter and Gamble supplied the soap and paid for the study.